火灾后圆钢管钢筋混凝土轴压短柱静力性能研究

发布时间：2018-03-31 03:40

本文选题：火灾后　切入点：圆截面钢管钢筋混凝土　出处：《辽宁工程技术大学》2014年硕士论文

【摘要】：钢管钢筋混凝土结构是指在普通钢管素混凝土中填充纵向受力钢筋,形成的一种新型组合结构。此种结构形式上虽然简单,但火灾作用下,内部钢筋在混凝土的保护下升温缓慢,强度损失小,提高其抗火性能；火灾作用后,钢材的强度能够得到恢复,力学性能比高温下有所改善,结构的整体性也比火灾中所提高,这不仅为结构的修复加固提供了一个较为安全的工作环境,也可减少工作量,降低维修费用。于是,本文对火灾后钢管钢筋混凝土轴压短柱进行了试验研究和有限元分析,主要工作如下：(1)本文对12根火灾后及6根常温下圆钢管钢筋混凝土轴压短柱进行剩余承载力试验研究和2根试件的温度场试验研究。研究表明试件的破坏模式均为剪切破坏,常温试件的剪切角为450左右,火灾后试件的剪切角为60°左右；受火时间是影响剩余承载力的主要因素,随着受火时间的增加,火灾后圆钢管钢筋混凝土轴压短柱剩余承载力随受火升温时间的增加而减小；配筋率对其剩余承载力的影响不大。(2)利用ABAQUS大型有限元软件建立火灾后钢管钢筋混凝土轴压短柱有限元分析模型,并与本文试验及收集到的相关试验数据进行验证,结果表明数据吻合较好,所建模型基本正确。(3)详细分析受火升温时间、截面尺寸、材料强度等参数对其剩余承载力系数的影响规律；进而回归出便于工程实践应用的火灾后钢管钢筋混凝土轴压短柱剩余承载力的简化计算公式。结果表明受火升温时间、截面尺寸是影响其剩余承载力系数的主要因素。
[Abstract]:Reinforced concrete filled steel tube (CFST) structure is a new type of composite structure, which is filled with longitudinal steel bars in plain concrete filled with steel tube.Although this kind of structure is simple in form, under the action of fire, the internal steel bar increases temperature slowly under the protection of concrete, the strength loss is small, and the fire resistance is improved. After the fire, the strength of steel can be restored.The mechanical properties are improved compared with those under high temperature, and the integrity of the structure is also improved compared with the fire. This not only provides a safe working environment for the repair and reinforcement of the structure, but also reduces the workload and maintenance costs.Therefore, the experimental study and finite element analysis of steel tubular reinforced concrete columns under axial compression are carried out in this paper.The main work is as follows: (1) in this paper, the residual bearing capacity of 12 reinforced concrete filled steel tubular columns under axial compression and the temperature field of 2 specimens are studied.The results show that the failure mode of the specimens is shear failure, the shear angle of the specimens at room temperature is about 450, the shear angle of the specimens after fire is about 60 掳, the fire time is the main factor affecting the residual bearing capacity, and with the increase of the fire time, the shear angle of the specimens is about 450, and the shear angle of the specimens after fire is about 60 掳.After fire, the residual bearing capacity of circular steel tubular reinforced concrete columns under axial compression decreases with the increase of heating time.The influence of reinforcement ratio on its residual bearing capacity is not significant. (2) the finite element analysis model of reinforced concrete filled steel tubular short columns under axial compression after fire is established by using ABAQUS software, and it is verified by the experimental data collected in this paper.The results show that the data are in good agreement, and the model is basically correct. (3) the influence of the temperature rise time, section size, material strength and other parameters on the residual bearing capacity coefficient is analyzed in detail.A simplified formula for calculating the residual bearing capacity of reinforced concrete filled steel tube short columns under axial compression after fire is obtained, which is convenient for engineering practice.The results show that the time of heating and the size of section are the main factors affecting the coefficient of residual bearing capacity.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU398.9;TU352.5

【参考文献】